Tianwan 7 VVER-1200 connects to grid, CNNC says

Unit 7 of the Tianwan nuclear power plant delivered its first electricity to the grid on October 8, China National Nuclear Corporation said. The VVER-1200 reactor reached a self-sustaining controlled chain reaction and was brought to a minimum controllable power level just over a week earlier.

Output will be raised in stages, with tests and checks at each level, until the unit reaches full power and commercial operation. CNNC said the unit will conduct a series of tests to verify its performance and confirm it meets the conditions for commercial operation.

Russia and China signed agreements in June 2018 to build two VVER-1200 reactors as units 7 and 8 at Tianwan. Construction of unit 7 began in May 2021 and of unit 8 in February 2022. The units were scheduled to enter commercial operation in 2026 and 2027.

The plant, on the coast in Jiangsu province, is owned and operated by Jiangsu Nuclear Power Company, a joint venture of CNNC (50%), China Power Investment Corporation (30%) and Jiangsu Guoxin Group (20%).

Hot tests at unit 7, which simulate the temperatures and pressures the reactor systems face in normal operation, were completed on December 30, CNNC said in January. Cold tests, which verify the leak-tightness of the primary circuit and components, were completed at unit 8 earlier that month.

The site's first four units, Gidropress VVER units supplied by Russia, began commercial operation between June 2007 and December 2018. Units 5 and 6 have Chinese ACPR1000 reactors. Once all units are operational, total installed capacity will exceed 9 GWe, with annual generation of more than 70 TWh and carbon dioxide emissions reduced by 57.4 million tonnes a year.